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The first Spacebus satellite, Arabsat-1A, was launched in 1985. Since then, fifty two have been launched, with four more completed, and twelve outstanding orders. The launch of the 50th Spacebus satellite, Star One C1, occurred in November 2007.[2] It was a Spacebus 3000B3, launched by an Ariane 5 rocket flying from the Guiana Space Centre in Kourou, French Guiana.

Several variants have been built: the early Spacebus 100 and Spacebus 300; followed by the Spacebus 2000, optimised for launch on the Ariane 4 carrier rocket; and the subsequent modular Spacebus 3000 and 4000 series, designed for use with the Ariane 5 rocket. Some Spacebus satellites are built using alternatives to US ITAR-controlled components, making it one of a few Western satellites that can be launched by Chinese Long March rockets.

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Aérospatiale had produced a number of satellites, including Symphonie, with the German company Messerschmitt. On 9 December 1983,[3] the two companies signed the Franco-German Spacebus Agreement. The Spacebus designation was first applied to satellites which were under construction by Aérospatiale when the programme started. These included three satellites for Arabsat, which became the Spacebus 100 series, and five further satellites: two for Deutsche Bundespost, two for TéléDiffusion de France, and the Swedish Space Corporation's Tele-X, which became the Spacebus 300 series. Later series' names were followed by a number indicating the approximate mass of the bus in kilograms.[4] Spacebus designations were not applied retrospectively to satellites which had already been launched.

Spacebus satellites consist of a satellite bus, which provides power, propulsion, and other subsystems necessary for the satellite's operation, and a payload which is customisable depending on the customer's requirements. The bus was designed to be adaptable to perform various missions; however, as of 2009, only communications satellites have been ordered. It was also designed to be adaptable when the capacity of launch systems increased.

The bus is made of carbon fibre with a composite honeycomb structure.[when?] It contains fuel tanks, equipment needed to interface with a carrier rocket, and other critical systems. Panels are attached to the outside of the structure with externally mounted equipment, including the solar panels, payload, and engine. The payload, which is developed separately from the bus, takes up three panels. Once it has been outfitted with transponders or other equipment, it is transported to Cannes-Mandelieu, where it is integrated onto the bus.

Spacebus satellites were developed to be compatible with a large number of available carrier rockets, particularly the Ariane family of rockets. As the performance of the Ariane has increased, the satellites have become larger to take advantage of this increased capacity.[5]

Three Spacebus 100 satellites were produced for Arabsat, to serve the 22 members of the Arab League.[6] One of the solar panels on the first satellite, Arabsat-1A, failed to deploy resulting in reduced power to the spacecraft. This, combined with gyroscope issues, resulted in it spending most of its operational lifespan as a reserve satellite.[7]

The Spacebus 3000 was introduced around the time the Ariane 5 entered service. Spacebus 3000 satellites have masses ranging between 2 to 6 tonnes (2.0 to 5.9 long tons; 2.2 to 6.6 short tons) and produce between 5 and 16 kilowatts (6.7 and 21.5 hp) of electrical power. Increasingly larger payload fairings allowed larger spacecraft to be produced. In 1991, the Satellite Alliance was formed, bringing together Aérospatiale, Alenia, and Space Systems/Loral.[5]

Nine B3 satellites were ordered, three for Eutelsat, two for Star One of Brazil, GE-12 for GE Americom, Turksat 2A for Turksat, and the Stentor experimental communications satellite for CNES. Stentor was lost in a launch failure on the maiden flight of the Ariane 5ECA.Galaxy 17 was successfully launched in 2007 for INTELSAT.[11]

The Spacebus 4000 series was derived from the 3000 series[14] but featured upgraded avionics. The voltage of the electrical system was increased from 50 volts to 100 volts, and an integrated onboard computer, designed to be more flexible than previous versions, was added. It was also the first satellite bus to be equipped with an attitude and orbit control system with star trackers designed for use in geostationary orbit.[14]

The B series used the same basic structure as the 3000 series. The C version had a base measuring 2.2 by 2.0 metres (7.2 ft × 6.6 ft). An ITAR-free version is also offered, which does not use components produced in the United States in order to avoid restrictions under US International Traffic in Arms Regulations. This allows ITAR-free satellites to be launched on rockets that are not approved by the US Government, including the Chinese Long March.[15]

Five Spacebus 4000B2 satellites have been ordered: Turksat 3A for Turksat, Thor 6 for Telenor of Norway, Nilesat 201 for Nilesat of Egypt,[16] Athena-Fidus for the French and Italian space agencies CNES and ASI,[17] and Sicral-2 for the Italian Ministry of Defence and the French Defence Procurement Agency (DGA), a contract worth about €295m in total.[18]

The fifth, Palapa D1 for Indosat, uses the ITAR-free configuration, and was launched by a Long March 3B in September 2009, but was initially placed in a low orbit.[20]Thales Alenia Space made corrections allowing the satellite to reach the planned geostationary transfer orbit on 3 September.[21] It finally reached geostationary orbit on 9 September.[22] It is now undergoing on-orbit testing upon its arrival at 113° East about mid-September, where it will be used to provide communications to Asia and Australia. It has enough fuel for 10 years of service, according to Reynald Seznec, President of Thales Alenia Space, instead of the planned 15 years due to the orbit-raising maneuvers.[23][24]

The first Rascom satellite, Rascom-QAF1, suffered a propulsion system failure during its first apogee manoeuvre on 21 December 2007. It was confirmed to have reached its final geostationary orbit at a longitude of 2.85° east on 4 February 2008, but with only two years of expected operational life, compared to the fifteen expected prior to launch.[25] On 9 September 2008, the Rascom-QAF1R satellite was ordered to replace it, also based on the 4000B3 bus.[26]

Eight Spacebus 4000C3 satellites, each of which has a height of 5.1 metres (17 ft) and generates 13 kilowatts (17 hp) of power, have been ordered. SES Americom and Eutelsat ordered two spacecraft each.[28][29] The Eutelsat spacecraft are being built using ITAR-free parts, and one of the satellites, Eutelsat W3B launched on an Ariane 5 on 2010-10-28 and was declared lost on 2010-10-30 due to a fuel leak.[30] Eutelsat 21B was ordered by 9 June 2010.;[31] and launched 10 November 2012;[32] Eutelsat W3D ordered on 3 December 2010;,[33] launched 2013-05-14;[34] Russian satellite operator Gazprom also ordered two satellites for its Yamal programme[35]—the first time it had procured Yamal spacecraft that were not manufactured in Russia. Only one will be a Spacebus, the second one is based on an Express-2000 platform.[36]

The Spacebus 4000C4 bus is 5.5 metres (18 ft) high and can generate 16 kilowatts (21 hp) of power with its solar panels. Four have been ordered so far: Ciel 2 for Ciel Satellite of Canada, which was launched on 10 December 2008,[37] and three spacecraft for Eutelsat, W2A,[38]W7, launched by Proton on 23 November 2009.[14] and Eutelsat-8 West B, ordered on 11 October 2012.[39]

On 6 December 2007, Thales Alenia Space signed an agreement with NPO PM of Russia to jointly develop the Ekspress-4000 bus, based on the Spacebus 4000.[40] The Ekspress-4000 is designed for direct injection into geostationary orbit by a Proton-M rocket.

In 2014, Thales Alenia Space start the development of a new family - Spacebus NEO - to address future market needs capitalizing on the strong heritage from Spacebus, with the Avionics 4000 in particular, and from Alphabus, while also incorporating an optimized mechanical architecture to offer a product with guaranteed long-term viability. These new platforms will offer state-of-the-art technologies and will be available in various propulsion versions, including an all-electric one. The all-electric Spacebus NEO, capable of carrying payloads weighing over 1,400 kg, and with power exceeding 16 kW, will be available starting in mid-2015.[41]

^Thales Alenia Space announced today that the Palapa-D communications satellite has been placed into a Geostationary Transfer Orbit (GTO), which will enable starting a nominal Launch Early Operation Phase, a Thales Alenia Space Press_Release, 3 September, on line www.thalesgroup.com